The following map of US congressional districts, (via the NY Times ), shows which district were "held" by Repubilcans (red), and which were "won" by Republicans, (red/black stripes). Dems are in Blue.
Keep in mind that there are still over a dozen races yet to be determined, (the ones shown in gray), more than half of which will likely fall the Republicans.
A few things really stand out when you see if this graphically:
1) The Democrats really are a largely "coastal" political party.
2) Despite being told that we had to back off of that "border control stuff", you'll notice that Republican challengers WON several districts along the US/Mexican border. I guess border control and a strong stance on immigration even sells in areas with a lot of - gasp! - immigrants!
3) The evolution of rural seats in the deep south towards the GOP is pretty much complete, (with the most of the exceptions being the majority black districts. These are districts that are conservative, but were held by long time Democrat incumbents. After next year's redistricting, they should remain in Republican hands for a long time.
4) New England has Republicans again. Joe Scarborough and other RINO's have complained that we didn't have any because we wouldn't let moderates get nominated. Looks like we're more successful when we nominate conservatives, huh?
5) Democrats got killed in the rust belt. So much for representing the "working families" of America. This will have a big impact on the 2012 presidential election in those states, as more GOP incumbent fundraising and campaign operations means more Republican voter turnout, (and again, those districts will be "drawn" even more Republican by then).
This is what happens when conservatives have more conservative candidates to get excited about...and when you have CLEAR differences between the parties.
All in all, a very good night.
Did I miss anything?